It has been known for many years to utilize, e.g., Greenland inland ice as a drinking water resource within the field of refreshing drinks or soft drinks based on the recognition that upon melting, the inland ice may be distributed to consumers as some of the purest naturally occurring water in the world. However, known methods have been disadvantageous, because some of the natural purity of the ice has been lost in the preparation of the ice as drinking water, after ice has been taken out from its natural occurrence, such as an iceberg. It has been necessary to melt the ice and then bottle or pack the water in containers permitting transport and distribution of the water to consumers.
This type of processing has been applicable not only to inland ice as can be found in Greenland, but is also useful in harvesting water from a glacier. Inland ice and glaciers are formed by yearly snowfall. Snowfall accumulates and compresses in an ice shelves over the course of many years to depths reaching over 4,000 meters in some areas. As the ice layers are compressed, and in the course of thousands of years, the ice moves towards ice rims and glaciers or other terminal points of the ice shelves. The glaciers calve and at short intervals yield an iceberg, which floats out to sea. These icebergs have typically been “caught” shortly thereafter before they are decomposed into undrinkable seawater. The ice is processed for the production of drinking water of a very high purity.
Glacial ice advances then retreats from year to year depending upon the climate around the glacier and typical snow accumulation. Glacier movements and shape shifting occur over very long periods of time (i.e., hundreds to thousands of years), but within historic memory such transformations in fewer than 100 years are not known. Presently, about 10 percent of the land in the world is covered with glaciers or ice shelves. Glaciers, ice shelves, ice caps and ice sheets store approximately 75 percent of the world's fresh water supply and cover over 15 million square kilometers. These frozen bodies of water have existed, as mentioned above, for thousands upon thousands of years. In Washington State alone, glaciers provide 470 billion of gallons of water each summer to consumers. Most of this water is used for drinking and the like. Furthermore, the Antarctic ice sheet has an age of over 40 million years.
There are several known techniques to determine the age of glaciers and ice sheets.
Most of these methods employ drilling an ice core from the glacier or ice sheet then counting the layers inside of the ice core, much like counting rings in a tree to determine the age of a tree. A first method of dating ice cores consists of counting the annual layers. The basis of this method lies with looking for items that vary with the seasons in a consistent manner. Of these are items that depend on the temperature (colder in the winter and warmer in the summer) and solar irradiance (less irradiance in the winter and more in the summer). Once such markers of seasonal variations are found, they can be used to find the number of years that the ice core has accumulated over. Of the temperature dependent markers, the most important is the ratio of 180 to 160. The water molecules composed of H2 (180) evaporate less rapidly and condense more readily than water molecules composed of H2 (160). Thus, water evaporating from the ocean starts off as H2 (180) poor. As the water vapor travels towards the poles, it becomes increasingly poorer in H2 (180), since the heavier molecules tend to precipitate out first. This depletion is a temperature driven process, so the precipitation becomes more enriched with H2 (160), then is the case in the summer. Thus, each annual layer starts 180 rich, becomes 180 poor and ends up 180 rich.
A second method of dating ice cores is to use the age of previously determined markers to determine the age of various points in the ice core. This relies on accurately previously dated ice cores with accurately placed markers on them as a point of reference to determine the age of another ice core. Alternatively, this method can compare certain inclusions in an ice core with inclusions of another ice core that has been dated. Typically, inclusions are ash from volcanic eruptions and acidic layers from various weather anomalies.
There exist many other known methods of dating ice cores taken from a glacier or ice sheet. Furthermore, gases collected that were trapped inside of a layer of a given ice core can be dated using standard carbon 14 and/or chlorine 36 dating. The point is that there exist many known methods to date an ice core and thus date various layers in a glacier.